Medical Bulletin 21/ January/ 2025 - Video

New research suggests that undernutrition may be exacerbating measles outbreaks in areas suffering from food insecurity. The findings are published in the journal nutrition.

A study involving over 600 fully vaccinated children in South Africa found those who were undernourished had substantially lower levels of antibodies against measles.

Researchers tracked the children's growth over time as an indicator of undernutrition and measured their antibody levels through blood tests. Children who were stunted around age three had an average of 24% lower measles antibody levels by age five compared to their typical-sized peers.

"We need to vaccinate children against infectious diseases that are preventable and ensure they are protected," said first author Brenda Eskenazi, Professor Emerita of Public Health at the University of California, Berkeley. "This is especially important now, given that many known diseases are expected to spread with climate change."

Reference: https://www.mcgill.ca/newsroom/channels/news/child-undernutrition-may-be-contributing-global-measles-outbreaks-researchers-find-362588

A new Cochrane review has found that calorie labelling of food on menus and products leads people to choose slightly fewer calories.

The research team examined evidence from 25 studies on the impact of calorie labelling on food selection and consumption. They found that calorie labels in supermarkets, restaurants and other food outlets led to a small reduction in the calories people selected and purchased. The average reduction was 1.8%, which would equate to 11 calories in a 600 calorie meal – or around two almonds.

The new update compiles evidence from 25 studies with a strong emphasis on real-world field settings, with 16 of the studies being conducted in restaurants, cafeterias, and supermarkets. The studies that were analysed encompassed over 10,000 participants from high-income countries including Canada, France, the United Kingdom and the USA. Only two of the studies included alcoholic drinks, and their results were too uncertain to draw any meaningful conclusions.

While calorie labelling shows promise, concerns remain about its possible impact on people at risk of disordered eating. The review noted a lack of data in the included studies on possible harms, including mental health impacts, and the authors recommend future research to assess this.

“Calorie labelling to reduce the calories that people consume remains somewhat contentious, both in terms of whether it has any effect, and whether potential benefits outweigh potential risks or harms,” says senior author Dr Gareth Hollands from the UCL Social Research Institute, also Senior Visiting Fellow at the University of Cambridge. “We can now say with considerable confidence that it does have a small but potentially meaningful effect on people’s food choices. Labelling may therefore have a useful role, ideally alongside a broader set of approaches that place more onus on industry rather than individuals, such as taxes, marketing restrictions and reformulation. However, we should not expect miracles, and any implementation of calorie labelling must balance the many potential positive and negative impacts of such policies.”

Reference: Clarke N, Pechey E, Shemilt I, Pilling M, Roberts NW, Marteau TM, Jebb SA, Hollands GJ. Calorie (energy) labelling for changing selection and consumption of food or alcohol. Cochrane Database of Systematic Reviews 2025, Issue 1. Art. No.: CD014845. DOI: 10.1002/14651858.CD014845.pub2. Accessed 17 January 2025.

Fetuses of pregnant people who gained excess weight in the first trimester of pregnancy show signs of excess fat distribution in the upper arm and in the abdomen, according to a study by researchers at the National Institutes of Health. These findings may inform efforts to prevent excessive weight gain early in life, a risk factor for adult obesity and related conditions, such as heart disease, high blood pressure and diabetes. The study appears in the American Journal of Clinical Nutrition.

The authors analyzed data from an earlier study of more than 2,600 singleton pregnancies, which included information on maternal weight before and during pregnancy and three-dimensional (3D) ultrasound scans (up to five) throughout pregnancy. The authors found that pregnant people with excessive weight gain—defined as more than 2 kilograms (about 4.4 pounds) in the first trimester—had fetuses with larger abdominal circumference and abdominal area and larger fetal arm fat thickness, when compared to pregnant people with adequate weight gain.

Fetuses from the excessive weight gain group continued to have greater arm thickness and abdominal measurements through the end of pregnancy, even when weight gain was not considered excessive during the second and third trimesters.

The authors wrote that their findings suggest that the timing of weight gain, instead of total weight gain, could be important for developing efforts to prevent excess fetal size and reduce the risk of heart disease and other conditions later in life.

Reference: Wagner KA et al. Relationship between gestational weight gain with fetal body composition and organ volumes in the NICHD Fetal 3D Study: A prospective pregnancy cohort. The American Journal of Clinical Nutrition (2024)

A new study has found that for people with HIV, current risk models underestimated cardiovascular events in both women and black men in high-income countries. Their findings are published in Lancet HIV. Researchers conducted a study to evaluate how well existing atherosclerotic cardiovascular disease risk estimates could be used to predict cardiovascular outcomes in global populations with HIV.

Their prospective cohort study used data from Randomized Trial to Prevent Vascular Events in HIV (REPRIEVE) to analyze individuals with HIV who were from low-, middle-, and high-income countries across several continents. The researchers found that for those in REPRIEVE, current risk models underestimated cardiovascular events in both women and black men in high income countries (HICs), while overestimating cardiovascular events for all people with HIV in low- and middle-income countries.

“These findings allow researchers to fine-tune cardiovascular disease prediction models for people living with HIV,” said Patrice Desvigne-Nickens, MD, a medical officer within the National Heart, Lung, and Blood Institute (NHLBI). “Assessing the accuracy of these predictions in subgroups of the population is possible because of carefully developed outreach and enrolling a diverse study population – representing all people at risk.”

Reference: Performance of the Pooled Cohorts Equations and D:A:D Risk Scores among Individuals with HIV in a Global Cardiovascular Disease Prevention Trial: A Cohort Study Leveraging Data from REPRIEVE